Changed layout of Variables window to support editable value
Public variables in other FungusScripts appear in the variable picker
popup menu.
Variables now have a public value property and remember their starting
value for when they are reset.
Disabled LoadGlobals / SaveGlobals commands.
Changed all variable classes to use simple public value variable.
Added FungusScript.GetPublicVariables()
Deleted GlobalVariables class.
Added Variables test scene